The four-story, 20,000-square-foot brick loft building at 39 Ainslie Street on the north side of Ainslie Street between Rodney and Keap Streets has nine residential units and an unoccupied ground-floor commercial space, BSP said.

“We love the neighborhood and the transformation that is going on there,” said David Manheimer, the co-founder of BSP, in prepared remarks. “We saw great potential in this property.”

BSP plans to rent the ground-floor commercial space and the upper floors as residential rental apartments.

“This building is classic old school Williamsburg,” said Benji Kohn, the co-partner of BSP, a development company specializing in purchasing and repositioning undervalued properties in Brooklyn. “It’s a great opportunity to make apartments in this type of space.”

According to property records the seller was Arm & Leg Co., an entity which had owned the site since 1999. The seller’s brokers were Cushman Wakefield’s Brendan Maddigan, Ethan Stanton and Mark Lively. The property had an $8 million asking price, according to marketing materials. “In a multiple bid process, the ultimate buyer was able to offer the seller a strong price and a flexible closing time frame which was key for the owner’s relocation,” said Mr. Maddigan in prepared remarks. It wasn’t immediately clear who BSP’s broker was in the deal.

BSP’s other Williamsburg holding is 136 North 8th Street, a four-story walk-up building. The company paid $2.4 million for the site last October, Department of Finance records indicate.

Update: This story was edited to include a comment from the seller’s broker.